target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
This patch changes vectored file I/O to use kmap + kunmap when mapping
incoming SGL memory -> struct iovec in order to properly support 32-bit
highmem configurations. This is because an extra bounce buffer may be
required when processing scatterlist pages allocated with GFP_KERNEL.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 8f6dae0..1fc5825 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -236,7 +236,7 @@
for_each_sg(sgl, sg, sgl_nents, i) {
iov[i].iov_len = sg->length;
- iov[i].iov_base = sg_virt(sg);
+ iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
}
old_fs = get_fs();
@@ -244,6 +244,8 @@
ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
set_fs(old_fs);
+ for_each_sg(sgl, sg, sgl_nents, i)
+ kunmap(sg_page(sg));
kfree(iov);
/*
* Return zeros and GOOD status even if the READ did not return
@@ -288,7 +290,7 @@
for_each_sg(sgl, sg, sgl_nents, i) {
iov[i].iov_len = sg->length;
- iov[i].iov_base = sg_virt(sg);
+ iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
}
old_fs = get_fs();
@@ -296,6 +298,9 @@
ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
set_fs(old_fs);
+ for_each_sg(sgl, sg, sgl_nents, i)
+ kunmap(sg_page(sg));
+
kfree(iov);
if (ret < 0 || ret != cmd->data_length) {